Processing and mechanical behavior of SiC fiber-reinforced Si3N4 composites

1991 ◽  
Vol 6 (9) ◽  
pp. 1926-1936 ◽  
Author(s):  
J-M. Yang ◽  
Steven T.J. Chen ◽  
S.M. Jeng ◽  
R.B. Thayer ◽  
J-F. LeCoustaouec
Keyword(s):  
Shear Strength ◽  
Mechanical Behavior ◽  
Interfacial Shear Strength ◽  
Indentation Test ◽  
Interfacial Properties ◽  
Interfacial Shear ◽  
Bending Test ◽  
Frictional Stress ◽  
Propagation Behavior ◽  
Sic Fiber

The interfacial properties and mechanical behavior of the SCS-6/Si3N4 composites fabricated by hot pressing from powder lay-up and tape lay-up techniques were studied. Interfacial shear strength and frictional stress were measured using an indentation test. Fracture toughness and work-of-fracture were measured using a three-point bending test on a chevron-notched specimen. The influence of interfacial shear strength on the toughening mechanisms and crack propagation behavior were investigated. The results indicate that the processing routes and fiber orientation will affect the interfacial properties, which in turn have a significant influence on mechanical properties.

scholarly journals Why Should the “Alternative” Method of Estimating Local Interfacial Shear Strength in a Pull-Out Test Be Preferred to Other Methods?

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2406
Author(s):  
Serge Zhandarov ◽  
Edith Mäder ◽  
Uwe Gohs
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Traditional Approach ◽  
Interfacial Shear ◽  
Frictional Stress ◽  
Displacement Curve ◽  
Pull Out ◽  
Alternative Method ◽  
Fiber Reinforced Materials ◽  
Force Displacement

One of the most popular micromechanical techniques of determining the local interfacial shear strength (local IFSS, τd) between a fiber and a matrix is the single fiber pull-out test. The τd values are calculated from the characteristic forces determined from the experimental force–displacement curves using a model which relates their values to local interfacial strength parameters. Traditionally, the local IFSS is estimated from the debond force, Fd, which corresponds to the crack initiation and manifests itself by a “kink” in the force–displacement curve. However, for some specimens the kink point is hardly discernible, and the “alternative” method based on the post-debonding force, Fb, and the maximum force reached in the test, Fmax, has been proposed. Since the experimental force–displacement curve includes three characteristic points in which the relationship between the current values of the applied load and the crack length is reliably established, and, at the same time, it is fully determined by only two interfacial parameters, τd and the interfacial frictional stress, τf, several methods for the determination of τd and τf can be proposed. In this paper, we analyzed several theoretical and experimental force–displacement curves for different fiber-reinforced materials (thermoset, thermoplastic and concrete) and compared all seven possible methods of τd and τf calculation. It was shown that the “alternative” method was the most accurate and reliable one, while the traditional approach often yielded the worst results. Therefore, we proposed that the “alternative” method should be preferred for the experimental force–displacement curves analysis.

Interfacial Shear Strength of Thin Polymeric Coatings on Glass

1988 ◽  
Vol 130 ◽  
Author(s):  
J. E. Ritter ◽  
L. Rosenfeld ◽  
M. R. Lin ◽  
T. J. Lardner
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Indentation Test ◽  
Interfacial Shear ◽  
Polymeric Coatings ◽  
Shear Tests ◽  
Glass Substrates ◽  
Lap Shear ◽  
Order Of Magnitude ◽  
Intrinsic Strength

AbstractThe interfacial adhesive shear strengths of epoxy and acrylate coatings on glass substrates were measured by the indentation and lap shear tests. The lap shear strengths were about an order of magnitude less and exhibited considerably more variability than those measured by indentation. It is believed that the lap shear strength is controlled by large processing flaws (pores in this study); whereas, the indentation test measures the “intrinsic” strength of the coating.

scholarly journals The Impact of Carbon Nanofibres on the Interfacial Properties of CFRPs Produced with Sized Carbon Fibres

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3457
Author(s):  
Zhenxue Zhang ◽  
Xiaoying Li ◽  
Simon Jestin ◽  
Stefania Termine ◽  
Aikaterini-Flora Trompeta ◽  
...  
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Fibre Diameter ◽  
Sheet Thickness ◽  
Interfacial Properties ◽  
Interfacial Shear ◽  
Nanoindentation Test ◽  
Carbon Nanofibres ◽  
The Impact ◽  
Push Out

In this work, different amounts of CNFs were added into a complex formulation to coat the CFs surfaces via sizing in order to enhance the bonding between the fibre and the resin in the CF-reinforced polymer composites. The sized CFs bundles were characterised by SEM and Raman. The nanomechanical properties of the composite materials produced were assessed by the nanoindentation test. The interfacial properties of the fibre and resin were evaluated by a push-out method developed on nanoindentation. The average interfacial shear strength of the fibre/matrix interface could be calculated by the critical load, sheet thickness and fibre diameter. The contact angle measurements and resin spreadability were performed prior to nanoindentation to investigate the wetting properties of the fibre. After the push-out tests, the characterisation via optical microscopy/SEM was carried out to ratify the results. It was found the CFs sizing with CNFs (1 to 10 wt%) could generally increase the interfacial shear strength but it was more cost-effective with a small amount of evenly distributed CNFs on CFs.

Interfacial Properties of As-Received and Coated SiC (SCS-6) Fiber Reinforced Reaction-Formed SiC Matrix Composites

1994 ◽  
Vol 365 ◽  
Author(s):  
Paula J. Gaeta ◽  
Richard D. Sisson ◽  
M. Singh ◽  
Jeffrey I. Eldridge
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Interfacial Shear ◽  
Ceramic Fiber ◽  
Second Phase ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Strength Failure ◽  
Sic Fiber ◽  
The Matrix

ABSTRACTThe possibility of improving the interfacial shear strength of the SiC fiber reinforced SiC matrix composite system was examined. A ceramic fiber coating was chosen based on availability and chemical stability with the fiber and matrix. Fiber push-out tests conducted on as-received and coated fiber reinforced composite samples allowed characterization of the interfacial shear strength. Average debond shear and frictional sliding stresses were calculated. The effects of sample thickness and second phase addition in the matrix were also evaluated. Tested samples were examined by SEM to determine the location of the interfacial failure and to determine if any interface reactions had occurred. The coating was then evaluated based on the resulting interfacial shear strength, failure location, and integrity of the interface as compared to those properties of samples reinforced with as-received fibers.

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